src/test/ui/typeck/assign-non-lval-needs-deref.rs

   1 // issue #101376
   2
   3 use std::ops::AddAssign;
   4 struct Foo;
   5
   6 impl AddAssign<()> for Foo {
   7     fn add_assign(&mut self, _: ()) {}
   8 }
   9
  10 impl AddAssign<()> for &mut Foo {
  11     fn add_assign(&mut self, _: ()) {}
  12 }
  13
  14 fn main() {
  15     (&mut Foo) += ();
  16     //~^ ERROR invalid left-hand side of assignment
  17     //~| NOTE cannot assign to this expression
  18     //~| HELP consider dereferencing the left-hand side of this operation
  19 }